Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
DIURNAL-VARIATION IN TOTAL AND UNDERCARBOXYLATED OSTEOCALCIN - INFLUENCE OF INCREASED DIETARY PHYLLOQUINONE
Autore:
SOKOLL LJ; BOOTH SL; DAVIDSON KW; DALLAL GE; SADOWSKI JA;
Indirizzi:
JOHNS HOPKINS MED INST,DEPT PATHOL,600 N WOLFE ST,MEYER B-125 BALTIMORE MD 21287 TUFTS UNIV,USDA,JEAN MAYER HUMAN NUTR RES CTR AGING BOSTON MA 02111
Titolo Testata:
Calcified tissue international
fascicolo: 5, volume: 62, anno: 1998,
pagine: 447 - 452
SICI:
0171-967X(1998)62:5<447:DITAUO>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
BONE GLA-PROTEIN; URINARY CALCIUM EXCRETION; VITAMIN-K-STATUS; SERUM OSTEOCALCIN; CIRCADIAN-RHYTHM; CIRCULATING OSTEOCALCIN; ANTICOAGULANT-THERAPY; PREMENOPAUSAL WOMEN; ORAL ANTICOAGULANT; MINERAL CONTENT;
Keywords:
DIURNAL VARIATION; OSTEOCALCIN; UNDERCAR BOXYLATED OSTEOCALCIN; PHYLLOQUINONE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
51
Recensione:
Indirizzi per estratti:
Citazione:
L.J. Sokoll et al., "DIURNAL-VARIATION IN TOTAL AND UNDERCARBOXYLATED OSTEOCALCIN - INFLUENCE OF INCREASED DIETARY PHYLLOQUINONE", Calcified tissue international, 62(5), 1998, pp. 447-452

Abstract

A diurnal variation exists in blood levels of the vitamin K-dependentbone protein osteocalcin. However, it is not known whether the carboxylated and undercarboxylated constituents of osteocalcin also vary. Therefore, osteocalcin and undercarboxylated osteocalcin were measured in specimens collected every 4 hours over a 24-hour period in nine healthy subjects (five males, four females) ages 20-33 years who were consuming a mixed diet containing 100 mu g of phylloquinone. Osteocalcin and undercarboxylated osteocalcin were measured by radioimmunoassay (RIA) before and after treatment with barium sulfate. Although the percent undercarboxylated osteocalcin did not change, a diurnal variation was observed in total osteocalcin, carboxylated osteocalcin, and undercarboxylated osteocalcin, with peak concentrations at 4 a.m. and the lowest concentrations between 12 p.m. and 4 p.m. The difference between the total osteocalcin peak and trough concentrations averaged 28 +/-:7 (SEM)%. There were no gender differences in these rhythms. The effect of dietary phylloquinone as a modulator of these rhythms was evaluatedin a randomized study by increasing phylloquinone intake to 420 mu g/day with fortified corn oil, split between the lunch and dinner meals. Total and carboxylated osteocalcin fluctuations and concentrations were not affected by the dietary treatment. The diurnal variation in undercarboxylated osteocalcin was abolished with supplementation and concentrations at 8 a.m. (14 hours following supplementation) (2.3 +/- 0.2ng/ml) were significantly lower than the unsupplemented levels (2.7 +/- 0.2 ng/mL, P = 0.006). The percentage of under carboxylated osteocalcin was similarly decreased after supplementation (19.7 +/- 1.3%) in relation to the mixed diet cycle (24.2 +/- 1.6%, P = 0.006) at 8 a.m. on the second day. Dietary supplementation induced a fluctuation in percentage undercarboxylated osteocalcin with a decline in levels starting at approximately 12 a.m. Therefore, additional dietary phylloquinone does not appear to modulate the total osteocalcin diurnal rhythm, but can influence its undercarboxylated component.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/11/20 alle ore 16:54:44